Analog Devices Inc./Maxim Integrated MAX6372KA

Overview

MAX6372KA from Maxim Integrated is a pin-selectable watchdog timer supervisor IC designed to monitor microprocessor activity in embedded systems. It features push-pull active-low watchdog output with 1ms pulse width, 60s fixed startup delay, and pin-selectable watchdog timeout from 1ms to 60s. It operates from +2.5V to +5.5V, draws only 8µA supply current, and is housed in an 8-pin SOT23 package for critical µP reset supervision in industrial controllers.

For engineers reviewing the MAX6372KA datasheet, MAX6372KA pinout, MAX6372KA application, or MAX6372KA equivalent, key selection criteria include its fixed 60s startup delay, push-pull WDO output (vs. open-drain alternatives), pin-selectable timeout configuration via SET0–SET2, and compatibility with low-power, space-constrained µP monitoring designs requiring deterministic reset timing.

Technical Context

The MAX6372KA implements a dual-phase timing architecture: a fixed 60s startup delay ensures full µP initialization before watchdog supervision begins, followed by a user-configurable timeout period determined by the logic states of SET0, SET1, and SET2 pins. Its push-pull WDO output drives low for ≥1ms without requiring external pull-up components.

Timing reconfiguration is supported dynamically-changing SET inputs triggers a 300µs internal setup time before new timing parameters take effect, and WDI transitions are ignored during both startup delay and setup periods. The device disables watchdog functionality when SET2=0, SET1=1, SET0=1, enabling software-controlled supervision enable/disable without power cycling.

Key Specifications

Pinout & Package

Package: 8-pin SOT23-8, surface-mount, lead-free or leaded options available; footprint compatible with industry-standard 8-pin SOT23 layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar watchdog timer applications.

Compared with MAX6370KA, MAX6372KA trades startup delay flexibility for guaranteed 60s initialization window - ideal for production systems with validated boot timing. Against TPS3808G33, MAX6372KA delivers superior design control via pin-selectable timeout, push-pull drive, and deterministic startup behavior - critical for medical and industrial certification paths.

Availability

MAX6372KA is available at Aetrix Electronics and suitable for industrial controllers, automotive body electronics, and medical device monitoring requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX6372KA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications applications.

The MAX6369–MAX6374 family was designed specifically for robust, pin-configurable µP supervision in environments demanding deterministic reset timing, low quiescent current, and minimal external components - targeting certified embedded systems.

FAQ

What is the watchdog startup delay for MAX6372KA?

The MAX6372KA has a fixed 60s startup delay - this period begins at power-up or after a timing configuration change and must elapse before the watchdog timer starts counting down the selected timeout period. This ensures the monitored microprocessor completes full initialization before supervision begins, preventing spurious resets during boot. The 60s value is not pin-selectable and applies regardless of SET0–SET2 states.

Does MAX6372KA require an external pull-up resistor on the WDO pin?

No, MAX6372KA does not require an external pull-up resistor on the WDO pin because it features a push-pull output stage. Unlike open-drain watchdogs (e.g., MAX6369), the MAX6372KA actively drives WDO high when deasserted and low when asserted - eliminating dependency on external components and simplifying PCB layout while ensuring clean, fast edges for reliable µP reset signaling.

How many watchdog timeout options does MAX6372KA support, and how are they selected?

The MAX6372KA supports eight discrete watchdog timeout options ranging from 1ms to 60s minimum, selected via the logic states of its three configuration pins: SET0, SET1, and SET2. These pins are sampled at power-up and after any configuration change, with timing values defined in Table 1 of the datasheet - for example, SET2=1, SET1=0, SET0=0 configures a 100ms timeout, while SET2=1, SET1=1, SET0=1 selects 60s.

Can MAX6372KA be disabled without power cycling?

Yes, MAX6372KA can be disabled without power cycling by setting SET2=0, SET1=1, SET0=1 - this configuration halts watchdog supervision entirely while maintaining power. The device remains powered and responsive; changing any SET pin state exits disable mode and initiates a new 300µs internal setup time before resuming supervision with the newly selected timing parameters.

What is the maximum supply voltage and operating temperature range for MAX6372KA?

The MAX6372KA operates over a supply voltage range of +2.5V to +5.5V and is rated for an operating temperature range of -40°C to +85°C. Its absolute maximum VCC is +6V, and junction temperature must not exceed +150°C. These specifications make MAX6372KA suitable for industrial and automotive environments where wide voltage tolerance and extended thermal performance are required.